Airgap/Disconnected Installation of OpenShift 4.2 (Updated)

Starting from OpenShift version 4.2, airgap/disconnected installation is supported. This paper established an opinionated way of setting up a local registry to install the OCP 4.2 for an airgap environment.

The following chart describes the steps at a high level. Setup a container registry with an internet connection, mirror the images for OCP, export those images into files. Then in the isolated environment, set up a container registry, import those image files thus to finish the local registry for the installation purpose.

Updates: The traditional save and load approach is not working. The image digest is changed. Instead, we need to use the skopeo tool to export the image into a directory on the source registry, then import the directory into the target registry.

Prepare the internet-facing VM

First, let's prepare a VM with internet access. Assume we are using a Ubuntu VM, install the necessary packages, podman, skopeo, htpasswd, as below,

sudo apt-get install software-properties-common -y
sudo add-apt-repository -y ppa:projectatomic/ppa 
sudo apt…